SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4403d8285a04833430a4affb507511e5056e5e9fca88f75a332348eb0ed24d9b' 
  AND token = 'NXKV/AFPuQrsTD7YpiF6OGEflKJBKRA4xFiqRIxQPNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}